Implantable infusion devices, which can deliver low levels of therapeutic agents to target locations in patients, have been employed or contemplated for treating a variety of diseases. Such implantable infusion devices are often permanently implanted and may be used to periodically or continuously deliver the therapeutic agent. To ensure continued delivery of the therapeutic agent to the patient over time, reservoirs of such devices need to be replenished. Typically such replenishment is accomplished by inserting a needle though the patient's skin and through a septum covering a port in fluid communication with the reservoir.
Because such a device is implanted and thus not able to be directly seen, care must be taken to ensure that the needle is properly placed into the device before injection. If the needle misses the device and, in particular, misses the drug reservoir in the device, the drugs will be immediately dispensed in the body, having potentially dire consequences for the patient. Moreover, if the needle is not fully placed through the septum and into the drug reservoir, the drug reservoir will not be adequately filled, also having potentially dire consequences for the patient.
Port locator devices have previously been described. Such devices are intended to be placed on the patient's skin adjacent the implanted infusion device. A hole or opening in the port locator is positioned over the reservoir port. A needle may then be inserted through the hole in the port locator, through the patient's skin, and into the reservoir port. Some of such port locator devices are designed to determine not only the location of the port relative to the needle, but also the alignment of the needle relative to the orientation of the port.
However, when determining orientation or alignment, the user-interfaces of such devices tend not to be straight forward. Given the importance of proper alignment of a needle with a port of an implanted infusion device prior to insertion of the needle into the port, a more intuitive interface to indicate alignment is needed.